QUESTION 8 FENCE Bob owns a business which makes fence posts. The length of these posts can be thought of as a random variable. When Bob's machines are calibrated correctly, the fence posts are produced with an average length of 250 cm and a standard deviation of 0.4 cm. The lengths ofthe individual fence posts are normally distributed. FENCE. What is the probability that an individual fence post is longer than 250.5 cm? A About 10.6% 'A About 39.4% A The answer cannot be calculated with the information given. 'A None of the above. QUESTION 9 FENCE Bob owns a business which makes fence posts. The length of these posts can be thought of as a random variable. When Bob's machines are calibrated correctly, the fence posts are produced with an average length of 250 cm and a standard deviation of 0.4 cm. The lengths ofthe individual fence posts are normally distributed. FENCE. Suppose a random sample of 49 fence posts is taken. What is the probability that the sample mean is longer than 250.5 cm? A About 100% A About 0% A The answer cannot be calculated with the information given. A None of the above. 1 points 1 points Save Answer Save Answer QUESTION 10 1 points Save Answer FENCE Bob owns a business which makes fence posts. The length of these posts can be thought of as a random variable. When Bob's machines are calibrated correctly, the fence posts are produced with an average length of 250 cm and a standard deviation of 0.4 cm. The lengths of the individual fence posts are normally distributed. FENCE. Suppose the length of the fence posts was not normally distributed. If you took a random sample of 49 fence posts, could you use the Z table to to calculate probabilities for the sample mean? O No. The fence posts must be normally distributed. No. We must use the t distribution instead. Yes but the calculation will not be very accurate. None of the above